It makes them better than they were yesterday.
Does it make them better than they were last year? This is clearly a treading water move, they literally brought back a guy that they had last year. He might be slightly better or healthier, but not vastly so.
Outside of that, as of now they've lost Sanchez, Bundy, and Archer who were at least tolerable contributors. They have brought in Gallo and Vazquez, which probably offsets those losses, but does that make them better? If Gallo turns back into an all star yes, but otherwise that's at best a tiny upgrade. They have brought up a couple of kids, but not a ton of them and not obviously guys who are franchise changing. Their bullpen should be better with a couple kids there, but that doesn't make up the ground against Cleveland.
So what are they counting on? They need guys who are there to stay healthier and perform better, including guys like in their starting rotation who have been hurt recently and regularly, and guys like their CF, who has all the talent in the world but keeps only playing half a season. That...sounds pretty familiar.